1. Field of the Invention
The present invention pertains to the chemical treatment of liquids, such as water for food processing and other uses.
2. Description of the Related Art
Many commercial and residential water supplies suffer from xe2x80x9chard waterxe2x80x9d and other objectionable conditions. In various types of commercial activities, such as produce handling, food stores and restaurants, the available domestic water supply is employed to carry out commercial operations. Remedial measures to address problems of corrosion and scaling, are sometimes carried out with the introduction of small amounts of a treatment chemical, such as polyphosphate or sodium silicate, into the domestic water supply.
A liquid treatment apparatus as described in commonly assigned U.S. Pat. No. 5,507,945 has proven commercially successful, particularly in the treatment of water supplies used for food preparation and other applications. The liquid treatment apparatus provides a chemical treatment agent which is put into solution and mixed with water flowing through the apparatus. More particularly, the liquid treatment apparatus includes a dispense head which develops a venturi action which is applied so as to help meter relatively small amounts of treatment chemical in the fluid flow. The liquid treatment apparatus includes, in addition to the aforementioned dispense head, a canister which threadingly engages the dispense head and which receives a container holding the chemical agent. Provision is made for joining the liquid treatment apparatus to a piping system. In operation, the canister is unthreaded from the dispensing head to allow replenishment of the chemical treating agent, provided in the form of a solid cake. While the chemical treatment apparatus has been met with widespread commercial acceptance, it is desirable to provide low cost alternative systems which are readily deployed by operators who are not familiar with dispenser and fluid metering technologies.
U.S. Pat. No. 5,580,448 discloses a chemical dispenser having a cartridge, used either alone or with an outer surrounding filter sleeve. The cartridge includes an apertured mid-section located between an upper solid wall conduit segment and a lower chemical-containing cartridge member which includes a dispensing aperture at its upper end. Thus, the amount of chemical treatment agent which can be provided, is reduced by the amount of the combined volume of the solid wall conduit segment and the apertured mid-section.
It is an object of the present invention to provide a treatment chemical suitable for introduction in relatively small amounts into a water supply.
Another object of the present invention is to provide a treatment chemical which can be readily metered into a water flow using conventional apparatus.
A further object of the present invention is to provide an improved method of manufacturing a treatment chemical in a solid, cake-like form.
Yet another object of the present invention is to provide a method which provides an orthophosphate, a phosphonate or the like water treatment chemical in a cake form having improved hardness, which resists disintegration under operational pressures and flows.
Yet another object of the present invention is to provide more rapid methods of manufacturing chemical treatment cakes of the above-described type.
These and other objects of the present invention are provided in a method of making a solid cake which is soluble in a dispensing device for dispensing a metered amount of treatment chemical into a water flow, comprising the steps of:
obtaining conventional polyphosphate, orthophosphate or phosphonate powder adapted to be mixed with water to form a solid;
mixing the powder with water to initiate an exothermic reaction and form a mixture having a temperature of at least approximately 120xc2x0 F.;
pouring the mixture in a mold vessel;
providing a cabinet defining a hollow interior;
placing the mold vessel within the cabinet;
maintaining the mixture within the cabinet so as to allow the temperature and humidity of the mixture to smoothly, continuously decay during transition of the mixture to a liquified solid form; and
removing the mold vessel from the cabinet after a sufficient amount of time has passed to allow the mixture to form a solid cake.